Low silver solder for welding the electric vacuum device and a preparation method thereof

Abstract

A silver solder for welding an electric vacuum device consisting of the following components in percentage by mass: 65-71% of Ag, 0-0.1% of Ni, 0-0.1% of trace element R and balance of Cu; the trace element R consists of one or more of P, Sc, Be, Zr and La. A method of producing the silver solder, comprising the steps of: evenly presetting Ag, Cu except from copper foil and Ni in a smelting crucible, placing the trace element R wrapped by the copper foil above the Ag, Cu except from copper foil and Ni, then smelting and casting the Ag, Cu but except from copper foil, Ni and the trace element R by adopting a vacuum induction smelting furnace, the vacuum degree of the furnace reaches 10 −1 Pa during smelting and casting, and finally a strip material or a wire material is prepared by a post treatment process.

What is claimed is: 
     
         1 . A low silver solder for welding an electric vacuum device, consisting of Ag, Cu, Ni and a trace element R, wherein the low silver solder consists of the following components in percentage by mass: 65-71% of Ag, 0.02-0.1 of Ni, 0.0001-0.1% of trace element R and the balance of Cu; the trace element R is selected from Sc, Be, Zr and/or La. 
     
     
         2 . The low silver solder according to  claim 1 , wherein a mass percent of the trace element R in the low silver solder is 0.0005-0.01 percent. 
     
     
         3 . The low silver solder according to  claim 1 , wherein a mass percent of the element Ni in the low silver solder is 0.05-0.08 percent.